Variable total internal reflection electrowetting lens assembly for a detector

ABSTRACT

Disclosed are examples of optical/electrical devices including a variable TIR lens assembly having a transducer, an optical lens and an electrowetting cell coupled to an exterior wall of the lens. The electrowetting cell contains two immiscible liquids having different optical and electrical properties. One liquid has a high index of refraction, and the other liquid has a low index of refraction. At least one liquid is electrically conductive. A signal causes the high index of refraction and the low index of refraction liquids to assume various positions within the electrowetting cell along the exterior wall. The properties of the optical lens, e.g. its total internal reflectivity, change depending upon the position of the respective liquids along the exterior wall. The light detection characteristics of the assembly change to receive an input light beam over a range of inputs or over a range of fields of view.

BACKGROUND

Devices have been available for some time that either detect light oroutput light. Some devices do both. In order to provide an indication ofdetected light or to output the light, a transducer may be used thateither responds to the detection of light by outputting an electricalsignal, or in response to an applied voltage or current emits light. Thetransducers that detect light or output light commonly requireadditional external optics to either vary the field of view or focus theoutput light.

In recent years, lighting devices that take advantage of total internalreflection (TIR) lenses have been used to provide light havingpredetermined characteristics, such as predetermined beam shape and beamdirection. For example, a TIR lens may collimate light from a sourcewithin the lighting device. Alternatively, TIR lenses having presetfields of view that are used for various light detection purposes, suchas detecting light directly in front of the detector so to obtain abetter indication of the presence of light in the vicinity of thedetector.

The TIR lens, however, has a fixed optic. Typically, a lighting deviceusing a TIR lens has to use external variable optics to selectivelyblock and redirect the light output from the TIR lens, if a user desiredany variation of the beam shape or the beam direction of the outputlight. Similarly, a detection device using a TIR lens also has to useexternal variable optics to selectively direct light toward the lightdetecting transducer.

A variety of variable optics are known among these, electro-fluidic orelectrowetting type optics are increasing in popularity for a variety ofapplications. An electrowetting lens enables variation in the beam shapeand/or beam direction of light passing through the electrowetting lens.However, the integration of the electrowetting lens with a lightingdevice lens has limitations with respect to the extent that beam shapingand beam steering that can be performed on the light output from a lensor the like of the lighting device lens.

Hence a need exists for improvement in extending the degree of beamshaping and beam steering that can be provided with a TIR lens equippedlighting device.

SUMMARY

Disclosed is an example of a detection device including a photoreceptivetransducer, a signal interface, a lens of a transparent material, and acontrollable electrowetting assembly. The photoreceptive transducer maybe configured to detect light and generate signals in response to thedetected light. The signal interface may be coupled to the transducer toreceive the generated signals from the transducer, and is configured tooutput detection signals based on the received generated signals. Thelens may be a transparent material having a first index of refraction.The lens includes an optical lens aperture, a lens interface and atransparent exterior lens wall. The optical lens aperture may beopposite the lens interface, and may be configured to receive light fromfield of view for direction through the transparent lens toward thetransducer. The lens interface provides light to the transducer. Thetransparent exterior lens wall extending from the lens interface to theoptical lens aperture. The controllable electrowetting assembly maysurround the transparent lens. The controllable electrowetting assemblymay be coupled to the signal interface and is configured to respond toelectrowetting signals received from the signal interface. Thecontrollable electrowetting assembly includes sealed container walls, ahigh index of refraction liquid a low index of refraction liquid, andelectrodes. The sealed container walls include at least one wall spacedabout the transparent lens, and form a fluidic sealed cell with theexterior wall of the transparent lens. The high index of refractionliquid and the low index of refraction liquid are contained in thesealed cell. One of the liquids is conductive and the other of theliquids is an insulator. The electrowetting optical aperture is throughone or more of the container walls and extends outward from the opticallens aperture. The electrodes are coupled to the signal interface andare electrically coupled with at least the low index of refractionliquid. The low index of refraction liquid may be responsive to theelectrowetting signals output from the signal interface, to vary anamount of the exterior wall of the transparent lens covered by the lowindex of refraction liquid. By varying an amount of the mount of theexterior wall of the transparent lens covered by the low index ofrefraction liquid, the total internal reflection of light within thetransparent lens is caused to thereby vary a direction and/or shape oflight received from the field of view via the electrowetting opticalaperture and/or the optical lens aperture.

Another example provides a device that includes a transducer and avariable lens assembly. The transducer converts optical energy into anelectrical signal. The variable lens assembly may be coupled to deliverlight to the transducer. The variable lens assembly includes astructurally static lens formed of a transparent material having a firstindex of refraction in a fixed shape and a controllable electrowettingcell. The structurally static lens includes a lens interface, an opticalaperture and an exterior wall. The lens interface may be at a proximalend of the shape to provide light to the transducer. The opticalaperture may be at a distal end of the shape opposite the proximal endto receive light from an environment in which the device is located. Theexterior wall extends from a portion of the lens interface to a portionof the optical aperture. The controllable electrowetting cell may becoupled to the exterior wall of the transparent lens. The controllableelectrowetting cell may be coupled to the exterior wall of thetransparent lens. The controllable electrowetting cell includes acontainer wall, an electrode, a high index of refraction liquid and anelectrically conductive low index of refraction liquid. The containerwall may be spaced from the exterior wall of the transparent lens. Thecontainer wall and the exterior wall of the transparent lens form afluidic leakproof container. The electrode associated with the containerwall to receive a control signal. The high index of refraction liquidand the electrically conductive low index of refraction liquid arewithin the container, and are immiscible. The high index of refractionliquid and the low index of refraction liquid, in response to a changeof the control signal, change positions within the electrowetting cellthereby altering internal light reflection characteristics of theexterior wall of the transparent lens.

Disclosed in yet another example is a variable optical detection devicethat includes a light detector, a variable lens assembly and electrodes.The light detector converts detected light into an electrical signal.The variable lens assembly directs input light toward the lightdetector, and includes a static, transparent total internal reflectionlens and a variable electrowetting cell. The lens has a first field ofview. The variable electrowetting cell includes a container, a highindex of refraction liquid and a low index of refraction liquid. Thecontainer forms a fluidically sealed space about the transparent lens.The high index of refraction liquid and the low index of refractionliquid are contained in the sealed space of the cell, and one of theliquids is conductive and the other of the liquids is an insulator. Theelectrodes are coupled to the variable lens assembly and at leastelectrically coupled with at least the low index of refraction liquid.The variable electrowetting cell is configured to change a first fieldof view of the lens assembly device to a second field of view, inresponse to an electrowetting signal applied via the electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord withthe present teachings, by way of example only, not by way of limitation.In the figures, like reference numerals refer to the same or similarelements.

FIG. 1 illustrates a cross-sectional view of a general example of alighting device incorporating an example of variable optical lensassembly utilizing an electrowetting cell to vary TIR.

FIGS. 2A and 2B illustrate in cross-section the working principles of anelectrowetting cell usable in the examples described herein.

FIG. 3 is a cross-sectional view of an example of a device having avariable TIR lens configured to detect light over a narrow field of viewand/or output a narrow beam of light.

FIG. 4A is a cross-sectional view of an example of a lighting devicehaving a variable TIR lens when configured to output an intermediatebeam of light.

FIG. 4B is a cross-sectional view of an example of a light detectiondevice having a variable TIR lens configured to receive light in anintermediate field of view.

FIG. 5A is a cross-sectional view of an example of a lighting devicehaving a variable TIR lens when configured to output a wide beam oflight.

FIG. 5B is a cross-sectional view of an example of a light detectiondevice having a variable TIR lens configured to receive light in a widefield of view.

FIG. 6A is a cross-sectional view of an example of a lighting devicehaving a variable TIR lens when configured to steer an output beam oflight in a specific direction.

FIG. 6B is a cross-sectional view of an example of a light detectingdevice having a variable TIR lens configured to receive an input beam oflight from a specific direction in relation to the variable TIR lens.

FIG. 7A is a plan view of a variable TIR lens assembly incorporating anexample of an electrowetting cell usable in a lighting or detectiondevice.

FIG. 7B is a plan view of a variable TIR lens assembly incorporatinganother example of an electrowetting cell usable in a lighting ordetection device.

FIG. 8 is a cross-sectional view of an example of a variable TIR lensassembly with a controllable external beam steering device.

FIG. 9 is a cross-sectional view of an example of a variable TIR lensassembly with a static external beam steering device.

FIG. 10 is a cross-sectional view of an example of a variable TIR lensassembly with additional electrowetting cells to provide additionalexternal beam steering device.

FIG. 11 is a cross-sectional view of an example of a variable TIR lensassembly with an alternate configuration of a variable lens assemblyincorporating electrowetting cells.

FIG. 12 is a simplified system diagram of a system having lightingdevices and detection devices incorporating variable TIR lensassemblies, such as those illustrated in any of FIGS. 1 and 3-11.

FIGS. 13A and 13B illustrate functional block diagram examples of asignal interface for use in devices incorporating variable TIR lensassemblies, such as those illustrated in any of FIGS. 1 and 3-12.

DETAILED DESCRIPTION OF EXAMPLES

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent that the presentteachings may be practiced without such details. In other instances,well known methods, procedures, components, and/or circuitry have beendescribed at a relatively high-level, without detail, in order to avoidunnecessarily obscuring aspects of the present teachings.

The various examples disclosed herein relate to a lens assembly withvariable TIR properties usable to output light that is input from alight source, a lighting device that uses lens assembly, a lensassembly, an apparatus, and an optical/electrical transducer apparatus.In several of the following examples, a refractive interface between astatic lens and fluids within an electrowetting cell will be describedas being a high index of refraction-to-a high index of refractioninterface (i.e., high-to-high refraction interface). However, in orderfor the desired TIR effects (such as suppressing the TIR) to beobtained, the refraction interface does not necessarily need to providean exact high-to-high ratio of indices of refraction. The suppression ofthe TIR effect may be obtained by using equal, or substantially equal,indices of refraction at the refraction interface between the staticlens and the electrowetting cells. For example, the refraction indexinterface ratios may be high-to-high, high-to-any higher,high-to-slightly lower, and the like. The index of refraction ratio atthe refraction interface for providing the desired TIR effect may bedetermined using Fresnel's equations. For ease of explanation, theinterface will be referred to as a high-to-high refraction interfacewhen the high index of refraction liquid is positioned along the neutralsurface of the optical lens.

The described examples use a variable lens assembly that includes anoptical lens, an electrowetting cell and electrodes. The optical lens isformed from a high index of refraction, transparent material, and has anexterior wall between an optical interface and an optical aperture. Theelectrowetting cell includes a wall coupled to the exterior wall of theoptical lens to form a fluidic sealed cell there between. A high indexof refraction liquid and a low index of refraction liquid are containedwithin the sealed cell by the wall and the optical lens exterior wall.The high index of refraction liquid and the low index of refractionliquid are immiscible, and at least one of the liquids is electricallyconductive. The electrodes are coupled to the optical lens exterior walland also receive control signals. The electrodes are configured to causethe high index of refraction liquid and the low index of refractionliquid to assume positions within the sealed cell along the optical lensexterior wall. In response to a control signal applied to theelectrodes, the positions of the high index of refraction liquid and thelow index of refraction liquid change to alter optical characteristicsof the lens assembly.

In a more specific example, the variable lens assembly includes anelectrowetting cell that contains fluids having different indices ofrefraction, which respond to electrowetting signals to change positionsof the fluids within the electrowetting cells. The variable lensassembly also includes a structurally static lens that is made from atransparent material having a high index of refraction of a fixed shape.Light is received from a light source via an optical input of the lens.When the fluids of the electrowetting cell are in one state, forexample, the optical interface between the fluid system of theelectrowetting cell and the exterior surface of the transparent materialof the lens is a high-to-low index of refraction interface. In such astate, the light from the light source is traveling from a high index ofrefraction material of the lens toward a low index of refraction fluid.As a result of the high-to-lower index of refraction interface,substantially all of the light within the static lens that encountersthe interface is reflected back into and toward an output of the lens byTIR. In this state, the lighting assembly has predetermined opticalcharacteristics. However, when the appropriate electrowetting signalsare provided, or applied, the fluid system of the electrowetting cellchanges to another state. The other state of the electrowetting cellcauses the optical interface between the electrowetting cell and theexterior wall surface of the transparent material to change tolower-to-low index of refraction interface. In other words, the index ofrefraction of the transparent material is now higher than the fluidindex of refraction presented by the fluid of the exterior wall. As aresult, the light within the lens material passes through the interfaceout to the lens (without TIR). In the other state, the lighting assemblyhas other optical characteristics different from the predeterminedoptical characteristics.

In another specific example, a detection device is disclosed thatutilizes a variable lens assembly and a transducer configured as a lightdetector. The variable lens assembly includes a structurally static lensand a controllable electrowetting assembly. The structurally static lensis formed of a transparent material that has a first index of refractionin a fixed shape. The static lens includes a lens interface and anoptical aperture. An exterior wall of the static lens extends from aportion of the lens interface to a portion of the optical aperture. Theoptical aperture acts as a light input and the lens interface is thelight output. The electrowetting assembly surrounds the transparent lensand includes a high index of refraction liquid and a low index ofrefraction liquid within sealed container walls. The low index ofrefraction liquid is responsive to the electrowetting signals, to varythe amount of the exterior wall of the transparent lens covered by thelow index of refraction liquid and cause total internal reflection oflight within the transparent lens to thereby vary a direction and/orshape of light received via an electrowetting optical aperture and/or anoptical lens aperture. The transducer converts optical energy into anelectrical signal. A signal interface provides the electrowettingsignals to electrodes coupled with at least the low index of refractionliquid of the electrowetting assembly and also receives electricalsignals generated by the transducer in response to any detected light.

Reference is now made in detail to the examples illustrated in theaccompanying drawings and discussed below. FIG. 1 illustrates across-sectional view of a general example of a variable optical lensassembly utilizing an electrowetting cell.

The example of FIG. 1 provides a lens assembly 100 that includes anoptical lens 110, a controllable electrowetting assembly 150, and anlens interface 130. The optical lens 110, for example, is a structurallystatic lens that includes the lens interface 130, the optical aperture135 and the longitudinal neutral surface, or exterior wall, 113. Theoptical lens 110 is a lens made of a transparent material having a firstindex of refraction, and is coupled to an optical/electrical transducer174 via the lens interface 130. The optical aperture 135 outputs lightfrom, or receives light provided to, the optical/electrical transducer174 from the optical lens 110. In general, the lens assembly 100 mayhave predetermined optical characteristics based on a configuration ofthe transparent, optical lens 110.

An optical/electrical transducer 174 is a device that converts betweenforms of optical and electrical energy, for example, from optical energyto an electrical signal or from electrical energy to an optical output.Examples of electrical-to-optical transducers include various lightemitters, such as a light emitting diode (LED) semiconductor, aplasma-based light emitter semiconductor, or an output of a fiber opticcable. In some examples, the emitted light may be in the visiblespectrum or in other wavelength ranges. The lens assembly 100 dependingupon its configuration has a transducer that emits light, such as lightsource 175 (described in more detail with reference to FIGS. 4A, 5A and6A), for output in various directions and beam shapes.

Examples of optical-to-electrical transducers include varioussemiconductor-based photo-sensitive sensors, such as a photodetector,photovoltaic devices and the like. For example, the photoreceptivetransducer 176 (described in more detail with reference to FIGS. 4B, 5Band 6B) may be configured with an optical energy sensor or detector,e.g. for UV, visible light, infrared, near-infrared, or the like; andwith a photovoltaic device for generating power in response to receivedoptical energy in a desired spectral range.

A device is also envisioned in which a transducer performs both lightemitting functions and light detection functions. Such a dual-functiondevice may operate through a multiplexing or time-division arrangementin which the function of the device changes based on predeterminedconditions (e.g., time of day, calendar day, temperature or the like) ora setting (e.g., light detection or light emission.)

In this example, the structurally static optical lens 110 is formed froma transparent material having a first index of refraction. For example,the optical lens 110 may be made from a high index of refractiontransparent material, such as glass, silicon as provided, for example,from Dow Corning™, a polycarbonate, an acrylic, other plastics or otheroptical quality transparent material. These materials are usable in thevisible light and near infrared spectrums other materials may be usedwhen the light is in the infrared or ultraviolet spectrums. The opticallens 110 has an neutral surface 113 between the lens interface 130 andan optical aperture 135. The neutral surface 113 extends from a portionof the lens interface 130 to a portion of the optical aperture 135. Theoptical lens 110 may have a structurally static shape (when viewed incross section that is curved, cylindrical, parabolic, pyramidal,frustum, or a combination of shapes (e.g., parabolic near the opticalinput 110 and cylindrical closer to the optical aperture 135). Whenviewed from the optical aperture 135 or the lens interface 130, theoptical lens 110 may have a substantially circular, oval shapedpolygonal or the like. In some examples, the neutral surface 113 forms acommon wall with the electrowetting cells 120.

The controllable electrowetting assembly, shown as 150A and 150B, spacedfrom the transparent optical lens 110 includes sealed container walls141-147 spaced about, or around, the transparent optical lens 110 thatform a fluidic sealed, or fluidic leakproof, cell; a high index ofrefraction liquid 163 and a low index of refraction liquid 165 containedin the sealed cell; electrowetting optical apertures 125; and electrodes(collectively, 155) coupled via signal interface 180 to a controller(not shown). Although the sealed container walls 141-147 refer toseveral walls, the sealed container walls may include at least one wall.The interior of sealed container walls 141 and 145 may also include ahydrophobic surface and insulator layer 88 opposite the exterior wallsof the optical lens 110. In some examples, the hydrophobic surface andinsulator layer 88 may include, or be formed from, a reflectivematerial, such that the hydrophobic surface and insulator layer 88 isreflective. The electrodes 155 may be associated with a respectivecontainer wall 141 or 145, and may be positioned between the hydrophobicsurface and insulating layer 88 and the respective container wall. Theelectrodes 155 are coupled to the signal interface 180 and a controller(shown in another example). In another example, the electrodes 155(e.g., anode) are associated with wall 145, and electrodes 154 (e.g.,cathode) may be associated with the surface of the electrowettingoptical aperture 125. When positioned in association with theelectrowetting optical aperture 125, the electrodes 154 may be formedfrom a transparent material, such indium tin oxide (ITO) or the like,that does not substantially alter the optical characteristics and/oroperation of the lens assembly 100. The other examples discussed belowmay also incorporate the electrodes 154; however, for ease ofillustration and discussion, the electrodes 154 are only shown anddiscussed with reference to FIG. 1. In addition, while theelectrowetting cell(s) 120 is described as fluidically sealed orleakproof, the electrowetting cells may not completely sealed. Forexample, a vented electrowetting cell may be provided that stillmaintains the fluidic/leakproof properties (e.g., non-spill) of theelectrowetting cell 120, but allows the interior of the cell to vent tothe environment.

An electrowetting cell, such as the one or more electrowetting cells120, is a sealed container that contains the high index of refractionliquid, or fluid, 163 and the low index of refraction liquid, or fluid,165. Note that the terms “liquid” and “fluid” as referred to herein areused interchangeably. The high index of refraction liquid 163 and thelow index of refraction liquid 165 are immiscible, and one of theliquids is conductive and the other of the liquids may be an insulator,such as water and oil. An oil may be, for example, a silicon-based oilor the like. The one or more electrowetting cells 120 are controllableoptical elements that change optical properties of the neutral surface(i.e., exterior wall) 113 of the lens assembly 100 based on controlsignals received via the interface 180, from a controller (not shown inthis example).

The electrowetting cells 120 include an electrowetting cell opticalaperture 125, which is a transparent wall, or transparent, opticaloutput, that is substantially parallel to the optical lens aperture 135.The electrowetting optical aperture 125 extends outward from the opticallens aperture 135, and toward the container walls 141-145. Theelectrowetting cell optical aperture 125 outputs light from the opticalelectrical transducer 174 when the lens assembly 100 is appropriatelyconfigured, as will be explained in more detail with reference to otherexamples. The one or more sealed container walls 141-147 may be coupledto the neutral surface 113 of the optical lens 110. For example, acontainer wall may be coupled to the neutral surface 1 113 of theoptical lens to form a fluidic sealed cell there between. The one ormore sealed container walls 141-147 and the electrowetting cell opticalaperture 125 may appear as continuous surfaces formed by molding thesealed container walls 141-147 with the neutral surface 113 of theoptical lens 110. Alternatively, the one or more sealed container walls141-147 electrowetting cell optical aperture 125 may be separatesurfaces that are spaced apart coupled using bonding agents, such asadhesives or, material coupling methods, similar to welding or the like,to the exterior of the neutral surface 113 of the optical lens 110 toform the electrowetting cells 120. A leakproof intersection between theone or more sealed container walls 141-147 and the neutral surface 113of the optical lens 110 form the electrowetting cell 120 of theelectrowetting assembly shown as 150A and 150B with the electrowettingcell optical aperture 125 also serving as a sealed container wall.

A high index of refraction liquid 163 and a low index of refractionliquid 165 are contained within the sealed cell walls 141-147 and theneutral surface 113. The high index of refraction liquid 163 and the lowindex of refraction liquid 165 are immiscible liquids, such as oil andwater, at least one of which is electrically conductive. In an example,the index of refraction of the high index of refraction liquid 163 ishigher than the first index of refraction of the transparent opticallens 110, and the index of refraction of the low index of refractionliquid 165 is lower than the first index of refraction of thetransparent optical lens 110.

An advantage of the disclosed examples is that the light outputproperties of the lens assembly 100 may be manipulated by controlsignals applied to the electrowetting assembly 150 to provide a varietyof output light beam shapes, or to steer output light beams indirections different from a single lens assembly. For example, theelectrowetting cells 120 may be controlled so that the lighting assembly100 provides a narrow output beam of light in a first configuration, andupon receipt of the appropriate electrowetting control signals, assumeanother configuration that provides a wider output beam of light.

The cross hatched area labeled T is a transition area within theelectrowetting cells 120 and, in order to control the position of theliquids 163 and 165 within the transition area T of the sealedelectrowetting cells 120, electrodes 155 are coupled to the one or morewalls of the electrowetting cells 120. Although, not shown in thisexample, when no control signals are applied, the transition area T maybe equally, or substantially equally, filled with the high index ofrefraction liquid 163 and the low index of refraction liquid 165. Theelectrodes 155 may also be coupled to the interface 180, which receivescontrol signals from an external controller (not shown in this example).For example, the electrodes 155 of the controllable electrowettingassembly extend along at predetermined positions along a length of thesealed container walls in a direction from the lens interface, 130 tothe optical lens aperture 135 of the transparent optical lens 110.

In a general example, the high index of refraction liquid 163 and thelow index of refraction liquid 165, in response to a receivedelectrowetting control signal, assume positions, such as the positionshown in the example and other positions within the transition region Tof the electrowetting cell(s) 120 along the neutral surface 113 of theoptical lens 110 that alter optical characteristics of the lens assembly100.

The volumes of the high and low index of refraction liquids shown inrespective FIGS. 1-11 are not shown to scale. In an actual systemincorporating an electrowetting cell, the volumes of the respectivevolumes of the high 163 and the low 165 index of refraction liquids isconserved when the liquids change position within the electrowettingcells 120. An alternative implementation is also envisioned in whichreservoirs (not shown) of the respective high index of refraction liquidand the low index of refraction liquid are fluidically coupled to theelectrowetting cell 120 via a sealed arrangement. A controller (asdescribed in later examples) may output respective control signals to areservoir management system (not shown), such as a pumping mechanism,plunger vacuum, or the like. In response to the control signal, thereservoir management system may cause either the intake excess fluidfrom or the output additional fluid into the respective electrowettingcell(s) to provide an even greater range of optical characteristics.

FIGS. 2A and 2B illustrate working principles of an electrowetting lensusable in the examples described herein. The relationships of the highand low index of refraction liquids are shown in FIGS. 2A and 2B, whichshow a cross-sectional representation of the sealed container walls ofthe controllable electrowetting assembly, such as electrowetting cell120 of FIG. 1. The sealed container walls of the electrowetting cell120, in the illustrated example, contains a low index of refractionliquid 210, a high index of refraction liquid and the sealed containerwalls include a hydrophobic insulating layer 230. The low index liquid210 could be an aqueous, or electrically conductive, liquid, such aswater, and the high index liquid 220 is transparent and may be asilicone oil, or other oil. The hydrophobic insulating layer 230 may,for example, be formed from Parylene C™, a dielectric stack such asAl2O3/Parylene C™, or the like. The hydrophobic insulating layer 230acts to diminish any residue from the respective liquids from remainingon the sealed container walls as the electrowetting assembly operates.In the examples of FIGS. 2A and 2B, the area to the right of thelongitudinal neutral surface of the optical lens 250 is the transparentoptical lens, such as 110. The electrodes 240A and 240B, for example,may be coupled to a signal source (not shown), such as a signalinterface, a controller, a current source or voltage source. One of theelectrodes, such as 240A, may be coupled to the voltage supply, and theother electrode, such as 240B, may serve as a ground or voltage supplyreturn electrode. When a controller applies a control signal, such as analternating-current (AC) voltage, between the electrodes 240A and 240B,a corresponding reaction between the liquids 210 and 220 is produced asexplained in more detail below.

The high index 220 and low index 210 of refraction liquids interactwithin a sealed container according to the following equation:

cos θ=cos θ₀+(∈V ²)/2γd  Eq. (1)

In equation (1), the variable θ represents the contact angle between thelow index of refraction liquid 210 and the high index of refractionliquid 220. In FIG. 2A, the angle θ₀ is the Young's angle, which is thecontact angle when a voltage is not applied to the electrodes 240A and240B. The angle θ₀ is determined based on the properties of the liquids210, 220 and the hydrophobic insulating material 230. The variable Vrepresents a value of the voltage applied to electrodes 240A and 240B.The variable ∈ represents the dielectric constant value of thehydrophobic insulating material 230. The variable d represents thethickness of hydrophobic insulating layer 230. The variable γ representsthe interfacial tension value between low index of refraction liquid 210and high index of refraction liquid 220. All of the values of thevariables are real numbers.

When a voltage is applied between electrodes 240A and 240B, the contactangle θ between the two liquids decreases. The contact angle θ decreasesas the applied voltage increases until the contact angle θ reaches asaturation contact angle θ_(min) between the layer 230 and a separationsurface (shown as a dash-dot-dash line) between the high index ofrefraction liquid 220 and low index of refraction liquid 210. Inoperation, the low index of refraction liquid 210 reacts to the voltageapplied to the electrodes 240A and 240B which causes the low index ofrefraction liquid 210 to assume a position within the electrowettingcell thereby allowing the high index of refraction liquid 220 to fillthe space evacuated by the low index of refraction liquid 210 adjacentto the transparent wall of the optical lens 250.

Depending upon a characteristic value of the applied voltage, such asmagnitude or frequency, the low index of refraction liquid 210 and thehigh index of refraction liquid 220 may change positions within thetransition region T (shown in brackets) of the sealed container.Depending upon the extent, or range, of the change in the position ofthe high index of refraction liquid 220, the optical properties of thetransparent wall of the optical lens, such as for example 110 of FIG. 1,also change. Said differently, the high index of refraction liquid 220has a first volume and the low index of refraction liquid 210 has asecond volume. The volumes of the high index of refraction liquid 220and the low index of refraction liquid 210 may be the same or different.Any alteration to the internal light reflection characteristics of thelens assembly when a control signal is received is based on thecontribution of the ratio of the volume of the high index of refractionliquid to the volume of the low index of refraction liquid.

For example, when the electrowetting cells are in the state shown inFIG. 2A, the light within the optical lens is reflected along thetransparent wall 250 of the optical lens and remains substantiallywithin the optical lens. Recall the above stated general rule that lightis reflected when transitioning from a high index of refraction mediumto a low index of refraction medium. In addition, the optical lens is ahigh index of refraction medium. In addition, if the incident angle ofthe incoming light is larger than the critical angle (followed theSnell's law) at any of the interfaces, the light, such as 275 will bereflected; otherwise, if the incident angle of the incoming light isless than the critical angle the light will pass through the interface.As a result of the transition region T within the electrowetting cellbeing filled with the low index of refraction liquid 210, the lightreflects and remains substantially within the optical lens and is outputfrom the optical lens aperture. In this configuration, a lightingapparatus outputs a narrower beam of light at the optical lens aperturein response to the low index of refraction liquid extending over alarger area of the one or more transparent lens wall than an area of theone or more transparent lens walls covered by the high index ofrefraction liquid. When the lens assembly is configured for use as adetector for detecting light and the liquids 210 and 220 are in thestate shown in FIG. 2A, the lens assembly has a narrow field of view aslight that enters an electrowetting aperture is substantially reflected(see Dashed Arrow 275) within the electrowetting cell due to theinterface of the high index of refraction liquid 220 with the low indexof refraction liquid 210. As a result, light that enters theelectrowetting aperture may not deliver any appreciable amount of lightto the optical lens interface and optical electrical transducer. In thisconfiguration, light that enters the optical lens aperture is directedby the combination of the electrowetting cells configuration shown inFIG. 2A and the optical lens toward the lens interface (not shown inthis example).

Conversely, when the state of the high index of refraction liquid 220and the low index of refraction liquid 210 changes to the state shown inFIG. 2B, the light from the optical lens is able to pass through to theelectrowetting cell. The light is able to pass because the transitionregion T is now filled with the high index of refraction liquid 220,which creates a high index of refraction-to-high index of refractionthat enables the light to pass through the electrowetting cell and out atransparent top portion of the electrowetting cell, such as 155. In thisconfiguration, a lighting apparatus outputs a wider beam of light at theoptical lens aperture in response to the high index of refraction liquidextending over a larger area of the one or more transparent lens than anarea of the one or more transparent lens walls covered by the low indexof refraction index liquid.

In response to different electrowetting control signals applied to oneor more of the electrodes 155, the lens assembly 100 is configured togenerate a narrower beam of light at the optical aperture in response tothe low index of refraction liquid 165 extending over a larger areaadjacent to the optical lens than the high index of refraction indexliquid 163. In other words, in response to an electrowetting controlsignal, the high index of refraction liquid 165 and the low index ofrefraction liquid 163 change positions within the electrowetting cellthereby altering internal light reflection characteristics of the lensassembly.

When the lens assembly configured for use as a detector for detectinglight and the liquids 210 and 220 are in the state shown in FIG. 2B, thelens assembly has a wider field of view as light that enters anelectrowetting aperture is substantially passed (see solid Arrow 276)within the electrowetting cell. As a result, light that enters theelectrowetting aperture or the optical lens aperture when the lensassembly is configured as explained with reference to the example ofFIG. 2B delivers light to the optical lens interface and opticalelectrical transducer.

The following examples illustrate the operation of the foregoing generalrule with respect to the lens assembly, such as lens assembly 100 ofFIG. 1.

FIG. 3 is a cross-sectional view of an example of a device having avariable optical lens configured to output and/or receive a narrow beamof light. In such a device, different components may perform oppositefunctions. For example, when the transducer 174 is a light source, thelens interface 130 acts as a light input to the optical lens 110 and theoptical aperture 135 and electrowetting aperture 125 act as lightoutput. Conversely, when the transducer 174 is a light detector, theoptical aperture 135 and electrowetting aperture 125 act as light inputsto the optical lens 110 and the lens interface 130 acts as a lightoutput from the optical lens 110 to the transducer 174. In the exampleof FIG. 3, the signal interface 180 receives electrowetting signals thatwhen applied to the electrodes 355A-355D cause the low index ofrefraction liquid 165 and the high index of refraction liquid 163 toassume the approximate positions shown in FIG. 3 with the liquidinterface 390 between the two liquids. For example, electrodes 355B and355C may be ground electrodes and electrodes 355A and 355D may havesubstantially the same electrowetting signals applied from a controllervia the signal interface 180. While the electrodes 355B and 355C areshown opposite the apertures 125 and 135, it is envisioned in someexamples that the electrodes may be substantially co planar with theapertures 125 and 135, and also be transparent or substantiallytransparent. The electrodes 355A and 355D may be associated with arespective exterior container wall of the electrowetting cell 120, andmay be positioned between the hydrophobic surface and insulating layer88 and the respective container wall.

Recall that the optical lens 110 is made from a high index of refractionmaterial, and that when light traversing a high index of refractionmaterial intersects with a material, such as liquid 165, having a lowerindex of refraction, any received or emitted light is reflected at theboundary of the two materials. As shown in FIG. 3, when the lensassembly 100 is being used for light emission, the optical/electricaltransducer 174 is a light source. The light output by theoptical/electrical transducer 174 light source is input into the opticallens 110 via the lens interface 130 intersects with the longitudinalneutral surface 113 at a number of different angles of incidence.Similarly, when the lens assembly 100 is being used for light detection,any light input into the optical lens 110 via the optical lens aperture135 also intersects with the longitudinal neutral surface 113 at anumber of different angles of incidence. In either case, the incidentlight (from the high index of refraction optical lens 110) passesthrough the longitudinal neutral surface 113 and intersects with the lowindex of refraction liquid 165.

As a result of the difference in refractive indexes between the opticallens 110 and the low index of refraction liquid 165, a substantialamount of the incident light is reflected from the low index ofrefraction liquid 165 back into the optical lens 110. As a result, whenthe light is emitted by the transducer 174, the reflected light isoutput from the optical lens aperture 135 in a narrow beam as outputlight 399. The narrow beam of output light 399 is output through theoptical lens aperture 135 in a direction substantially perpendicular toa vertical axis of the optical lens 110. In this particular example, anarrow beam of light including light 399 is output only from the opticallens aperture 135. Similarly, when light from the environment in whichthe device is located is received via the optical lens aperture 135, thereflected input light (also illustrated as light beam 399) is directedinward to the lens interface 130 which further directs the incominglight beam 399 toward the optical/electrical transducer 174. Theoptical/electrical transducer 174, when configured as a detector,converts the incident light into an electrical signal for output to thesignal interface 180.

As shown in the example of FIG. 3, when the lens assembly 100 is beingused for light emission, the shape and/or direction of light output viathe electrowetting optical lens aperture and/or the optical lensaperture is varied to produce a narrower output beam of light output inresponse to the low index of refraction liquid extending over a largeramount of the transparent lens wall than the high index of refractionindex liquid. Similarly, when the lens assembly 100 is being used forlight detection, the direction of light input via the electrowettingoptical lens aperture 125 and/or the optical lens aperture 135 arevaried to produce a narrower field of view in response to the low indexof refraction liquid extending over a larger amount of the transparentlens wall than the high index of refraction index liquid. In otherwords, the liquid interface 390 minimizes the amount of light thatenters the optical lens 110 through the electrowetting cell 120.

However, other beam steering and/or shapes or light detection fields ofview are also contemplated such as an intermediate beam shape/field ofview. Examples of a variable TIR lens assembly configured to provide anintermediate beam shape or an intermediate field of view for lightdetection are illustrated respectively in FIGS. 4A and 4B. In theexample of FIG. 4A, the lens assembly 400 is configured for use with atransducer 175 that emits light. In this configuration, theelectrowetting optical aperture 125 and the optical lens aperture 135are light outputs of the electrowetting cells 120 and the optical lens110, respectively, and the lens interface 130 is a light input to theoptical lens 110 for light emitted by the light emitting transducer 175.In the example, the signal interface 180 receives electrowetting signalsthat when applied to the electrodes 355A-355D cause the low index ofrefraction liquid 165 and the high index of refraction liquid 163 toassume the approximate positions shown in FIG. 4A with the liquidinterface 490 between the two liquids. For example, electrodes 355B and355C may be ground electrodes and electrodes 355A and 355D may respondto the electrowetting signals received from a controller (not shown inthis example) via the interface 180. As mentioned with reference to FIG.3, the electrodes 355A and 355D may be associated with a respectiveexterior container wall of the electrowetting cell 120, and may bepositioned between the hydrophobic surface and insulating layer 88 andthe respective container wall.

The interface 180 also outputs signals to the light source 175 based ontransducer control signals received from the controller. The lightemitted by the light source 175 into the lens interface 130 is outputfrom the lens interface 130 into the optical lens 110 at various angles.Some of the light input to the lens interface 130 enters the opticallens 110 at shallower angles, such as light 391. In the illustratedexample, the light 391 when exiting from the neutral surface 113 of theoptical lens 110 intersects the low index of refraction liquid 165. As aresult, the light 391 is reflected back into the optical lens 110 andoutput through the optical lens aperture 135 as output beam 499. Inaddition, light output by the light source 175 also enters the opticallens 110 at higher angles, such as light 395. Light 395 output from theoptical lens 110 intersects the high index of refraction liquid 163 whenexiting the optical lens 110. As a result, the light 395 is passedthrough the high index of refraction liquid 165 at an anglesubstantially equal to the angle of incidence with the longitudinalneutral surface 113, and is output through the high index of refractionliquid 163 as output beam 498.

FIG. 4B is a cross-sectional view of an example of a light detectiondevice having a variable TIR lens configured to receive light in anintermediate field of view. In the example of FIG. 4B, thephotoreceptive transducer 176 is configured to detect light, and basedon the lens assembly configuration 401 may have an intermediate field ofview. In this configuration, the electrowetting optical aperture 125 andthe optical lens aperture 135 are light inputs of the electrowettingcells 120 and the optical lens 110, respectively, and the lens interface130 outputs light from the optical lens 110 for detection by thephotoreceptive transducer 176. The photoreceptive transducer 176generates electrical signals in response to the detected light that areoutput to the signal interface 180.

For example, input light, represented by light beam 492, enters theoptical lens 100 through the optical lens aperture 135 and intersectsthe neutral surface 113 at a point at which the high index of refractionliquid 163 is located along the neutral surface 113. As a result, someof the input light, such as light represented by arrow 492, passesthrough the neutral surface 113 of the optical lens 110, and enters theelectrowetting cell 120. When inside the electrowetting cell 120, theinput light 492 may further reflect, but is essentially input light thatis undetectable by the photoreceptive transducer 176. Conversely, otherinput light, represented by arrow 493 enters the optical lens aperture135 at a steeper angle than input light 492, and intersects with theneutral surface 113 at a point at which the low index of refractionliquid 165 is located along the neutral surface 113. As a result, theinput light beam 493 is reflected toward the lens interface 130 andphotoreceptive transducer 176. Hence, the low index of refraction liquid165 is responsive to the electrowetting signals output from the signalinterface 180, to vary an amount of the exterior wall of the transparentlens 110 covered by the low index of refraction liquid 165 and causetotal internal reflection of light within the transparent lens 110 tothereby vary a direction and/or shape of light received via theelectrowetting optical aperture 125 and/or the optical lens aperture135. In another example, the light beams 495 enter the electrowettingoptical aperture 125 passing into a region occupied by the high index ofrefraction liquid 163. Since the interface between the electrowettingoptical aperture 125 and the external environment of the light assembly,in this case, air, is a low-to-high index of refraction interface, theinput light beams 495 are reflected toward the optical lens 110. In suchan example, the light beams 495 pass through the high index ofrefraction liquid 163 and the neutral interface 113. The interfacebetween the high index of refraction liquid 163 and the optical lens 110is a high-to-high index of refraction interface so the light beam 495passes substantially unimpeded toward the lens interface 130 and thetransducer 176. In addition, the incident angle of the input light 495must be considered. For example, in order for the input light beam 495to pass through both the low-to-high index of refraction interface(between the electrowetting optical aperture 125 and high index ofrefraction liquid 163 of the electrowetting cell 120) and thehigh-to-high index of refraction interface (between the high index ofrefraction liquid 163 and the optical lens 110), the incident angle ofthe input light 495 must be, according to Snell's Law, less than thecritical angle.

In some examples, the lighting assembly 100 is configured, in responseto control signals applied to one or more of the electrodes 355A-355D toalso output wider beams of light out of the optical aperture 135 and theelectrowetting apertures 125, or receive light over a wider field ofview, in response to the high index of refraction liquid 163 extendingover a larger area adjacent to the optical lens than the low index ofrefraction index liquid 165. The electrodes 355A and 355D may beassociated with a respective exterior container wall of theelectrowetting cell 120 and may be positioned between the hydrophobicsurface and insulating layer 88 and the respective container wall.

FIG. 5A is a cross-sectional view of an example of a lighting devicehaving a variable optical lens configured to output a wide beam oflight. In the example of FIG. 5A, the interface 180 receives controlsignals that when applied to the electrodes 355A-355D cause the lowindex of refraction liquid 165 and the high index of refraction liquid163 to assume the approximate positions shown in FIG. 5A with the liquidinterface 590 between the two liquids. For example, electrodes 355B and355C may be ground electrodes and electrodes 355A and 355D may respondto control signals received from a controller via the interface 180. Theelectrodes 355A and 355D of FIGS. 5A and 5B may be associated with arespective exterior container wall of the electrowetting cell 120, andmay be positioned between the hydrophobic surface and insulating layer88 and the respective container wall.

In the example of FIG. 5A, the light source 175 is configured as a lightemitter. The light emitted by the light source 175 is received by thelens interface 130 and input into the optical lens 110 at variousangles. In other words, in the example of FIG. 5A, light is input intothe optical lens 110 through the lens interface 130 and is outputthrough the optical aperture 135, the electrowetting aperture 125, orboth. Some of the light input via the lens interface 130 enters theoptical lens 110 at shallower angles, such as light 591. In theillustrated example, the light 591 output from the optical lens 110intersects the high index of refraction liquid 163 when exiting theoptical lens 110. As a result, the light 591 is passed through thelongitudinal neutral surface 113 of the optical lens 110 and outputthrough the electrowetting optical aperture 125 as output beam 599. Inaddition, light output by the light source 175 also enters the opticallens 110 at higher angles, such as light 595. Light 595 output from theoptical lens 110 intersects the high index of refraction liquid 163after exiting the longitudinal neutral surface 113 of the optical lens110. As a result of the positions of the liquids 163, 165 in theelectrowetting cells 120, the light 591 and 595 is passed through thehigh index of refraction liquid 163 at an angle substantially equal tothe angle of incidence with the longitudinal neutral surface 113, and isoutput from the respective electrowetting optical aperture 125 as outputwide beams 598 and 599.

As a result of the configuration shown in FIG. 5A, the direction and/orshape of light output via the electrowetting optical aperture 125 and/orthe optical lens aperture 135 is varied to produce a wider beam ofoutput light in response to the high index of refraction liquid 163extending over a larger amount of the transparent lens wall of theoptical lens 110 than the low index of refraction index liquid 165.

FIG. 5B is a cross-sectional view of an example of a light detectiondevice having a variable TIR lens configured to receive light in a widefield of view.

In the example of FIG. 5B, the variable lens assembly 501 is coupled toa photoreceptive transducer 176. The variable lens assembly 501 includesa structurally static lens 110 formed of a transparent material having afirst index of refraction in a fixed shape. Similar to the example of5A, the static optical lens 110 includes a lens interface 130 and acontrollable electrowetting cell 120. However, in contrast to thevariable lens assembly example of FIG. 5A, light in the variable lensassembly example of FIG. 5B is input into the optical aperture 135,electrowetting apertures 125A and/or 125B and light is output from thelens interface 130.

In the light detector example of FIG. 5B, input light 598 and 599 enterthe electrowetting cell 120 through the light inputs, electrowettingoptical apertures 125 and the optical lens aperture 135, and intersectthe neutral surface 113 at a point at which the high index of refractionliquid 163 is located. As a result, the input light 598 and 599 passthrough the neutral surface 113 of the optical lens 110, and enter theoptical lens 100 now shown as light beams 595 and 591, respectively. Theinput light 595 and 591 is further directed toward the photoreceptivetransducer 176 by the lens interface 130 for detection by the transducer176. While input light 598 and 599 is shown entering only via theelectrowetting optical apertures 125 in the wide field of view exampleof FIG. 5B, it should also be understood that the input light enters thelens assembly 501 across the full width of the electrowetting opticalapertures 125 and the optical lens 135. In addition, the angles ofincidence of the input light 595 and 599 must be considered. Forexample, in order for the input light 595 and 599 to respectively passthrough both the low-to-high index of refraction interface (between theelectrowetting optical aperture 125 and high index of refraction liquid163 of the electrowetting cell 120) and the high-to-high index ofrefraction interface (between the high index of refraction liquid 163and the optical lens 110), the incident angle of the input light 595(shown within circle A) and input light 599 (shown within circle B) mustbe, according to Snell's Law, less than the critical angle.

While the examples of FIGS. 3, 4A and 5A illustrated controllable outputlight beam shaping, the example illustrated in FIG. 6A shows a lightingassembly controlled to provided beam steering.

FIG. 6A is a cross-sectional view of an example of a lighting devicehaving a variable TIR lens when configured to steer an output beam oflight in a specific direction. The structure of the lighting assembly600 is similar to the structure described above with reference toFIG. 1. In particular, the one or more electrowetting cells,collectively referred to as 123, as shown in FIG. 6A have two separatelycontrollable portions, 123A and 123B, for ease in explaining thedifferences in the response to the voltages applied at the respectiveelectrodes 355A-355D. Similarly, the transparent electrowetting opticaloutput, collectively referred to as 125 of previous examples is nowreferred to as 125A and 125B to facilitate easier description of theconfiguration differences of FIG. 6A as compared to the previousexamples of FIGS. 1, 3A, 4A and 5A. FIGS. 6A and 6B also show ahydrophobic surface and insulator layer 88 on the walls of theelectrowetting cell 120 that is opposite the exterior walls of theoptical lens 110. In some examples, the hydrophobic surface andinsulator layer 88 may include, or be formed from, a reflectivematerial, such that the hydrophobic surface and insulator layer 88 isreflective. Discussion of some of the structural details of similarlylabeled elements is omitted in the following discussion since thefunctional aspects of those elements in the examples of FIGS. 6A and 6Bare unchanged from the previous examples.

In the example of FIG. 6A, the interface 180 receives electrowettingsignals that are applied as electrical voltages or currents to theelectrodes 355A-355D. The interface 180 may also receive control signalsfor sending signals to, or receiving signals from, the light source 175.The interface 180 may be configured to determine (using, for example,electronic circuitry, firmware, or a microprocessor) which electrodesare to have a voltage (or current) applied in response to the receivedelectrowetting signals. Alternatively, the interface 180 may simply be aconnector board that facilitates a wired connection to the opticalassembly 600 including electrodes 355A-D and light source 175. Theelectrodes 355B and 355C may be ground electrodes and electrodes 355Aand 355D may be control electrodes. In more detail, a electrowettingsignal is received at the interface 180 from a controller (not shown inthis example). In response to the received electrowetting signal, theinterface 180 applies a first voltage between control electrodes 355Aand 355B on the 123A portion of the electrowetting cell 120 that causesthe low index of refraction liquid 165 to assume a position along thetransparent wall of the optical lens 110 shown by the liquid interface670. Also, in response to the received electrowetting signals, theinterface 180 applies a second voltage to electrodes 355C and 355D onthe 123B portion of the electrowetting cell 120 that causes the lowindex of refraction liquid 165 to assume a position along thetransparent wall (i.e., longitudinal neutral surface 113) of the opticallens 110 shown by the liquid interface 671.

The light output by the light source 175 into the lens interface 130 isdispersed at various angles when output from the lens interface 130 intothe optical lens 110. Some of the light output from the lens interface130 enters the optical lens 110 at shallower angles, such as light 691.With the liquids 163 and 165 configured in the respective electrowettingcells 123A and 123B as shown, the emitted light 691 exits the opticallens 110 and passes through the longitudinal neutral surface 113 andintersects the high index of refraction liquid 163. As a result ofpassing from a high index of refraction medium (i.e., optical lens 110)into another high index of refraction medium (i.e., high index ofrefraction liquid 163), the light 691 passes through the longitudinalneutral surface 113 of the optical lens 110 without substantialrefraction, enters the electrowetting cell 123B, and is output throughthe electrowetting optical aperture 125B as output light beam 699. Thebeam steering functionality of FIG. 6A is further illustrated by thelight beam 695 which is prevented from substantially being output fromthe electrowetting optical aperture 125A. In the example, the light beam695 is output toward electrowetting optical aperture 125A. However, dueto the response of the high index of refraction liquid 163 and low indexof refraction liquid 165 in electrowetting cell 123A to thevoltage/current applied to the respective electrodes 355A and 355B, thelight 695 is reflected back into the optical lens 110 and output via theoptical lens aperture 135. As a result of the electrowetting signalsapplied to the respective electrodes 355A-355D, the light outputdirection of the light emitted by the light source 175 is set. Theelectrodes 355A and 355D of FIGS. 6A and 6B may be associated with arespective container wall of the electrowetting cell 120, and may bepositioned between the hydrophobic surface and insulating layer 88 andthe respective container wall.

In addition, light, such as light 695, output by the light source 175also intersects the transparent wall of the optical lens 110 at higherangles. Light 695 intersects the low index of refraction liquid 165after exiting the longitudinal neutral surface 113 (i.e., thetransparent wall) of the optical lens 110. As a result of the respectivepositions of the liquids 163 and 165 in the electrowetting cells 123Aand 123B, the light produced by the light source 175 is directed, orsteered, away from the electrowetting optical aperture 125A and steeredtoward the electrowetting optical aperture 125B of electrowetting cell123B and the optical lens aperture 135 for output from the lens assembly600.

While the example of FIG. 6A shows a beam steering capability of alighting assembly in one direction, it should be understood that thebeam steering capability may be controlled to steer the output beam inother directions around the perimeter of the lighting assembly 600. Forexample, by application of different voltages to the respectiveelectrodes 355A-D, the positions of liquids 163 and 165 in theelectrowetting cells 123A and 123B may change so that the output lightbeams are steered toward electrowetting optical aperture 125A foroutput. Based on the received electrowetting signals, other beamsteering configurations are also possible.

FIG. 6B is a cross-sectional view of an example of a light detectingdevice having a variable TIR lens configured to receive an input beam oflight from a specific direction in relation to the variable TIR lens. Inthe variable lens assembly example of FIG. 6B, in contrast to thevariable lens assembly example of FIG. 6A, light is input into theoptical aperture 135, electrowetting apertures 125A and/or 125B andlight is output from the lens interface 130. The example of FIG. 6B whenthe light assembly 600 is used with a photoreceptive transducer 176configured as a light detector. When configured as a light detector, thephotoreceptive transducer 176 responds to detected light. The lensassembly 600 may be configured to bias the direction from which light ismore readily detected by the photoreceptive transducer 176. For example,light 694 enters the light assembly 600 via the electrowetting opticalaperture 125A passes through the high index of refraction liquid 163 andintersects with the low index of refraction liquid 165. In response tothe intersection with the low index of refraction liquid 165, the light694 is directed away from optical lens 110 and does not providemeaningful light to the photoreceptive transducer 176. Other light 692and 693 enters the optical lens 110 through the optical lens aperture135. Due the angle of entry into the optical lens 110, the light 692intersects and passes through the neutral surface 113, the light 692 isreflected by the low index of refraction liquid 165 back into opticallens 110 and toward the lens interface 130 and photoreceptive transducer176. The photoreceptive transducer 176 in response to the detected lightgenerates an electrical signal that is output to the signal interface180. Conversely, light 693 enters the optical lens 110 at a differentplace and angle than light 692. Light 693 intersects and passes throughthe neutral surface 113, the light 693 passes into the the high index ofrefraction liquid 163, where it may reflect multiple times and does notprovide meaningful input light to the photoreceptive transducer 176.

The examples of FIGS. 5B and 6B are examples of the variableelectrowetting cell configuration in which a field of view of thevariable lens assembly is changed from a first field of view, e.g., widefield of view, to a second field of view, e.g., directed field, inresponse to an electrowetting signal applied via the electrodes coupledto the variable lens assembly.

As shown in the examples of FIGS. 3-6B, the lens assembly 100 isconfigurable, in response to electrowetting signals applied to one ormore of the electrodes, such as 355A-D, to output wider beams of light,or receive light over a wider field of view at the optical lens aperture135 in response to the high index of refraction liquid 163 extendingover a larger area adjacent to the optical lens 110 than the low indexof refraction index liquid 165. Both the optical beam shaping andsteering settings and the field of view settings are also infinitewithin the physical constraints of the respective lens assemblies300-601 and the applied electrowetting signals. In addition, theforegoing examples also illustrate a lens assembly, such as 100 and300-601, in which the low index of refraction liquid is responsive toelectrowetting signals, applied to the electrodes 355A-D from a signalinterface. The electrowetting signals cause a variation in the area ofthe transparent lens exterior wall (i.e., 113) covered by the low indexof refraction liquid 165 thereby causing a total internal reflection oflight within the transparent, optical lens 110. The variations in thecoverage of liquids 163, 165 may be used to vary a direction and/orshape of light output via the electrowetting optical aperture 125 and/orthe optical lens aperture 135.

In addition to varying the signals applied to the electrodes of theelectrowetting cells to provide different beam shaping and/or beamsteering attributes to the output light, the number of electrowettingcells 120 may also be varied. For example, instead of the one or moreelectrowetting cells described in the examples of FIGS. 1 and 3-6B, thefollowing examples illustrate plan views of variable optical lensassemblies some of which include multiple electrowetting cells.Depending upon the configuration, the following examples may includemultiple electrowetting optical apertures, and a plurality of electrodesthat manipulate the immiscible liquids with the respectiveelectrowetting cells.

FIG. 7A is a plan view of a variable optical lens assembly incorporatinga first example of an electrowetting lens and a static optical lens. Theplan view of the variable optical lens assembly 700 of FIG. 7A islooking into the optical lens aperture of the optical lens 710 and theelectrowetting cell 720. For reference, in a light emittingconfiguration, light output from the lens assembly 700 would be comingout of the page, while in a light detection configuration, light wouldbe input into the page. For example, the optical lens 710 may beparabolic as shown in the examples of FIGS. 1 and 3-6 in which case theground electrode 755G is located close to the vertex of the parabolicoptical lens 710. Of course, other shapes such as cylindrical, oval,polygonal, square and the like are also envisioned. In this example, theelectrowetting cell 720 is a single electrowetting cell surrounding theoptical lens 710. Since the low index of refraction liquid 765 and thehigh index of refraction liquid 763 are immiscible, in this view, thehigh index of refraction liquid 763 is on top of the low index ofrefraction liquid 765 (shown by the dashed line). The exterior walls ofthe electrowetting cell 720 includes a hydrophobic and insulator layer725 that facilitates movement of the liquids 763, 765 within the cell720 by reducing surface tension and acts as a barrier between electrodes755A-D and the respective liquids 763 and 765. Similarly, the opticallens 710 has an exterior surface that is a hydrophobic surface 714 thatforms an internal surface of the cell 720. The hydrophobic surface 714also facilitates movement of the liquids 763, 765 within the cell 720.An signal interface, not shown in this example, but such as interface180 of FIG. 1, is coupled to a controller and to the respectiveelectrodes 755A-755G. The high index of refraction liquid 763 and thelow index of refraction liquid 765, in response to signals applied fromor through the signal interface between one or more of controlelectrodes 755A-755D and ground electrode 755G, assume positions withinthe electrowetting cell 720 that provide an output light beam having abeam shape and beam direction corresponding to the applied signals.

Electrodes 755A-D may be further segmented into multiple, individuallycontrollable electrodes on a same side of the variable optical lensassembly 700. When a desired optical lens assembly configuration isindicated, for example, by a controller, the same or differentpotentials from the interface 180 may be applied to one or more of themultiple, individually controllable electrodes to achieve the desiredoptical lens assembly configuration.

Other configurations of the lighting device assembly may include morethan one electrowetting cells. FIG. 7B is a plan view of a variableoptical lens assembly incorporating a another example of anelectrowetting lens. The variable optical lens assembly 701 of FIG. 7Bincludes optical lens 710, four electrowetting cells 720A, 720B, 720Cand 720D, control electrodes 766A-766D and ground electrode 766G. In theillustrated example, electrowetting cell 720B includes a low index ofrefraction liquid 775, a high index of refraction liquid 773, a portionof hydrophobic surface 717 and a hydrophobic surface and insulator 727.In some examples, the hydrophobic surface and insulator 727 may include,or be formed from, a reflective material, such that the surface 727 isreflective. Each of the remaining three electrowetting cells 720A, 720Cand 720D include the same elements as electrowetting cell 720B. Theelectrowetting cells 720A-D are separated from one another by barriers788A-D. The barriers 788A-D may also serve as walls of the respectiveelectrowetting cells 720A-D bordered by the barriers 788A-D. Whenserving as walls of the electrowetting cells 720A-D, the barriers 788A-Dseal the liquids 775 and 773 within the respective electrowetting cells720A-D.

In response to electrowetting control signals, such as a voltage orcurrent, applied by or through the signal interface between one or moreof control electrodes 766A-766D and ground electrode 766G, the highindex of refraction liquid 773 and the low index of refraction liquid775 assume positions within the electrowetting cell 720. The positionsassumed by the liquids 773 and 775 may provide, in some examples, anoutput light beam having a beam shape and beam direction correspondingto the applied signals. Alternatively, when the lens assembly 700 isused with a light detector, the application of the electrowettingsignals facilitates detection of light from a selected direction withreference to the lens assembly 700. The selected direction being basedon a field of view configuration determined by the positions assumedhigh index of refraction liquid 773 and the low index of refractionliquid 775 within the electrowetting cell 720.

In a related example illustrated in FIG. 7B, the barriers 788A-D may befilled with a liquid, such as a low index of refraction liquid that actsto reflect any dispersed light toward the optical output of therespective electrowetting cell 720A-720D. In another alternative, theground electrode 755G is shown as a single ground electrode. However,each of the respective electrowetting cells 720A-720D may have aseparate ground electrode, which may facilitate some form of biasing ofeither the beam shaping or beam steering functions, as well as field ofview settings, of one or more of the respective electrowetting cells720A-720D.

In an alternative example, the variable optical lens assembly 700 mayalso include additional electrodes 767A-D along the barriers 788A-D. Theadditional electrode 767A-D provide an additional level of control ofthe respective electrowetting cells 720A-D. For example, a signalinterface may be configured to deliver signals to the respectiveelectrowetting cells 720A-720D.

In yet another alternative example, while the additional electrodes767A-D are shown as single electrodes, each of the additional electrodes767A-D may include multiple electrodes separated in the middle by aninsulating layer. The insulating layer prevents the signals applied tothe respective electrodes for interfering with one another. Thisconfiguration would allow different signals within the barriers 788A-Dto be delivered to adjacent electrowetting cells, such as, for example,720A and 720B, or 720A and 720D.

FIG. 8 is a cross-sectional view of an example of a variable opticallens assembly with a controllable external beam steering device. Thevariable optical lens assembly 800 includes, in addition to lensassembly elements described in the prior examples, a beam steeringoptics 880 that are located over the optical outputs 825 and 835 of anoptical lens assembly 860 similar to the examples of FIGS. 1 and 3-6.

Specifically, the beam steering optics 880 are positioned over theelectrowetting optical outputs, such as 125 of FIGS. 1 and 3-6, and theoptical lens output, such as 135 of FIGS. 1 and 3-6. The beam steeringoptics 880 may include a number of controllable optical elements (notshown) that are configurable to direct light output from the opticallens assembly 860 in various directions. The controllable opticalelements that comprise the beam steering optics 880 may include, forexample, polarization gratings, liquid crystal polarization gratings,electrowetting cells, liquid crystal diffusing elements, or the like.The beam steering optics 880 are coupled to a signal interface 870,which applies voltage or current signals to the beam steering optics 880to control the configuration of the optical elements. In response tosignals received from the interface 870, the beam steering optics 880are configured to steer, or redirect, the light into (when transducer875 is configured to detect light) and out (when transducer 875 isconfigured to emit light) from the electrowetting optical aperture 825and/or the optical lens aperture 835. The shape of the beam steeringoptics 880 may be annular, a rectangular array, a linear array, circularor the like.

The structural elements of the optical lens assembly 860 are similar tothe variable lens assemblies shown in the examples of FIGS. 1 and 3-6B,and a detailed discussion of those similar items is omitted in thefollowing discussion of FIG. 8 for the sake of brevity. In addition,although only examples of light output are described, the beam steeringoptics 880 and optical lens assembly 800 including interface 870 andtransducer 875 may also be configurable as a light detector. As a lightdetector, the optical lens assembly 800 is configured to receive inputlight via a controllable field of view through the beam steering optics880 and the optical aperture 835 and/or electrowetting apertures 825.The field of view is determined by the configuration of the beamsteering optics 880, the electrowetting cells 820 and the opticalcharacteristics of the optical lens 110.

The signal interface 870 connects to the electrodes, collectively shownas 855, that control the positioning of the liquids 863 and 865. Thespecific example of FIG. 8 is similar to the example of FIG. 3 as theoptical lens assembly 860 is configured by positioning of the liquids863 and 865 to output a narrow beam of light as beams 898 and 899. Forexample, the light output by the transducer 875 into the optical lensinterface 830 disperses at various angles. Some of the light input tothe optical input 830 enters into the optical lens 810 at shallowerangles, such as light 891 as well as steeper angles, such as 895. Due tothe positions of liquids 863 and 865, as explained with reference to theexample of FIG. 3, the beams of light 891 and 895 are reflected into theoptical lens 810, and are output from the optical aperture 835 of theoptical lens 810. Without any beam steering provided by the beamsteering optics 880, the beams of light 895 and 891 would output theoptical lens aperture 135 and pass through the beam steering optics 880in the general direction of beams 892 and 893.

As shown in FIG. 8, the beam steering optics 880 are configured tosteer, or redirect, the light beams 892 and 893 in the directionsindicated by arrows 898 and 899 in response to optics control signalsreceived from, for example, the signal interface 870. As a result, thelight output from the controllable variable lens assembly 800 is morenarrowly focused in response to signals received via the signalinterface 870 from a controller (not shown in this example). Otherexamples of external beam shaping and beam steering optics are alsoenvisioned.

FIG. 9 is a cross-sectional view of an example of a lighting device witha static external beam steering device. The variable optical lensassembly 900 includes a static beam steering device 980 that is locatedover the optical output of an optical lens assembly 960 similar to theexamples of FIGS. 1 and 3-6.

Specifically, the beam steering device 980 is positioned over theoptical lens aperture 935, which is similar to the optical lens aperture135 of FIGS. 1 and 3-6. The beam steering device 980 may include anumber of static optical elements such as TIR optics, a surfacetreatment, electrowetting lenses, a liquid crystal polarization grating(LCPG), a microlens or the like that are configured to further focuslight output from optical lens aperture 935 of the optical lens assembly960. In the illustrated example, the beam steering device 980 is notlocated over the electrowetting optical apertures 925. In addition,since the beam steering device 980 is a static optical element, it isnot coupled to a signal interface 970. The signal interface 970 connectsto the electrodes, collectively shown as 955, that control thepositioning of the liquids 963 and 965.

The structural elements of the optical lens assembly 960 are similar tothe variable lens assemblies shown in the examples of FIGS. 1, 3-6 and8, and a detailed discussion of those similar items is omitted in thediscussion of FIG. 9 for the sake of brevity.

The specific example of FIG. 9 is similar to the example of FIG. 3 asthe optical lens assembly 960 is configured by positioning of theliquids 963 and 965 to output a narrow beam of light as beams 995 and991. For example, the light output by the transducer 975 into theoptical input 930 disperses at various angles. Some of the light inputto the optical input 930 enters into the optical lens 910 at shallowerangles, such as light 991 as well as steeper angles, such as 995. Due tothe positions of liquids 963 and 965, as explained with reference to theexample of FIG. 3, the beams of light 991 and 995 are reflected into theoptical lens 910, and are output from the optical output 935 of theoptical lens 910. The beam steering device 980 by further focusing theoutput light beams 995 and 991 mitigates dispersion of the light outputfrom the variable lens assembly 900. The shape of the beam steeringdevice 980 may be annular, a rectangular array, a linear array, circularor the like.

FIG. 10 is a cross-sectional view of an example of a variable opticallens assembly with additional electrowetting cells to provide additionalexternal beam steering device. The variable optical lens assembly 1000includes a lens assembly 1060 and additional electrowetting optics 1090.The lens assembly 1060 in the example of FIG. 10 is substantiallysimilar to the lens assemblies 860 and 960 shown in the examples ofFIGS. 8 and 9, and therefore, any detailed discussion of the lensassembly 1060 is omitted.

The additional electrowetting optics 1090 are positioned over theoptical lens aperture 1035, similar to static beam steering device 980of FIG. 9. The additional electrowetting optics 1090 and the lensassembly 1060 are coupled to a signal interface 1070 in a similar manneras explained in previous examples. The additional electrowetting optics1090 respond to voltage or current signals received from the signalinterface 1070 to provide additional beam steering or beam shaping tolight that is output from the optical lens 1010. Alternatively oroptionally, additional optics 1091 may be positioned over theelectrowetting optical apertures 1025 to provide additional beam shapingor beam directing functionality. While the lens elements 1181, 1082,1088 and 1091 are referred to as static, it is also envisioned that thelens elements may be controllable lens elements such as polarizationgratings, liquid crystal gratings and/or electrowetting cells.

FIG. 11 is cross-sectional view of an example of a variable optical lensassembly with an alternate configuration of a variable lens assemblyincorporating electrowetting cells. Similar to the static external beamsteering device example of FIG. 9, the example of FIG. 11 includesstatic lens elements 1181, 1182 and 1188. In the example, the variableoptical lens assembly 1100 includes the optical lens assembly 1160 andthe static lens elements 1181, 1182 and 1188. Similar to the staticexternal beam steering device example of FIG. 9, the example of FIG. 11includes static lens elements 1181, 1182 and 1188. The optical lensassembly 1160 includes an optical lens 1110 surrounded by andelectrowetting cell 1120. The electrowetting cell 1120 is a fluidicleakproof, sealed container that contains a high index of refractionliquid 1163 and low index of refraction 1165. Electrodes 1155 arepositioned on walls of the electrowetting cell 1120. Light may be outputfrom the electrowetting cell 1120 via transparent, electrowettingoptical apertures 1125. The electrowetting optical apertures 1125 arepositioned about an optical aperture of the optical lens 1110.Alternatively or in addition, optional static lens elements 1191 may bepositioned over the electrowetting optical apertures 1125 to provideadditional beam shaping or beam directing functionality. While the lenselements 1181, 1182, 1188 and 1191 are referred to as static, it is alsoenvisioned that the lens elements may be controllable lens elements suchas polarization gratings, liquid crystal gratings and/or electrowettingcells.

The functional features of the electrowetting cell 1120 may be similarto the electrowetting cells, such as 120 described with reference toFIGS. 1 and 3-6.

The optical lens 1110 is made of similar materials as optical lens 110described with reference to FIGS. 1 and 3-6. However, the optical lens1110 includes a lens interface 1132 that extends within the optical lens1110 and focuses the light emitted by transducer 1175 toward the opticallens output and the additional lens device 1188. The additional lens1188 may be configured to focus light received from the lens interface1132 and other areas of the optical lens 1110 for output from theoptical lens 110. The additional lens 1181 and 1182 may be totalinternal reflection (TIR) lens elements. The additional lens 1181 and1182 may be different sides of an annular lens positioned over opticallens 1110. Alternatively, lens 1181 and 1182 may be individual arraysthat extend across the optical lens 1110. The lens 1181 and 1182,whether collectively or individually, may be a polarization grating, amicrolens or the like.

FIG. 12 is a simplified system diagram of a lighting system havinglighting devices incorporating variable optical lens assemblies, such asthose illustrated in any of FIGS. 1 and 3-11. FIG. 12 shows a premises15 having an illuminated space or area 13 in which a lighting device 67incorporates a variable lens assembly (VLA) 76. The lighting device 67may include a VLA 76 and a signal interface 87 as described in any ofthe examples of FIGS. 1 and 3-11. The signal interface 87 (described inmore detail with reference to the example of FIGS. 13A and 13B) mayreceive control signals that are applied directly to the variable lensassembly 76 of the lighting devices 67. Alternatively, any controlsignals received by the signal interface 87 may be converted to signalsthat are then applied to the variable lens assembly 76.

Also shown is a detector device (DD) 68 in which the VLA 78 isconfigured for use as a light detecting device. The optical/electricaltransducer in the VLA 78 is configured as a light detecting device thatoutputs, or causes the output of, a signal in response to detectedlight, for example, a visible light communication code as emitted by themobile device 25 in the illuminated space or area 13, or ambient lightin the illuminated space or area 13. The interface 88 (described in moredetail with reference to the example of FIGS. 13A and 13B) may receivelight detection signals from the VLA 78 that are either processed by theinterface 88 or are passed to a server, such as server 29.

The data network 17 in the example also includes a wireless access point(WAP) 21 to support communications of wireless equipment at the premises15. For example, the WAP 21 and network 17 may enable a user terminal,such as mobile device 25 for a user to control operations, such as thebeam shaping and beam steering as described with reference to FIGS. 3-11of any lighting device 67 or detector device 68 at the premises 15.However, the ability to control operations of a lighting device 67 ordetector device 68 may not be limited to a user terminal accessing datanetwork 17 via WAP 21 or other on-premises access to the network 17.Alternatively, or in addition, a user terminal such as laptop 27 locatedoutside premises 15, for example, may provide control signals to one ormore lighting devices 11 via one or more other networks 23 and theon-premises network 17. Network(s) 23 includes, for example, a localarea network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN) or some other private or public network, such as theInternet. Alternatively or in addition, a server, such as server 29,coupled to a database, such as database 31, may control the variableoptical assemblies 76 by sending control signals to the signal interface87 of the respective lighting devices 67 or interface 88 of detectordevice 68. In addition, different control signals may be sent todifferent lighting devices 67 within the same illuminated space or area13 to provide customized lighting effects, such as task lighting, thatare provided by lighting devices 67 cooperating to provide the desiredlighting effect. Alternatively or in addition, different control signalsmay be sent to different detection devices 68 within the sameilluminated space or area 13 to provide customized responses to detectedlights, such as controlling a co-located lighting device 67, controllinga building function, such as turning on air conditioning or some otherfunction, or the like. The devices 25, 27 and 29 may act as externalcontrollers that are coupled to the respective signal interface 87 ofthe LD 67 and/or signal interface 88 of the DD 68.

The examples of FIGS. 1 and 3-12 refer to a signal interface, such as180 and 87. Examples of interfaces are shown in the functional blockdiagram examples of FIGS. 13A and 13B.

In FIG. 13A, the signal interface 1387 may be integrated in a lightingdevice, a light detection device, or a device having both lighting anddetection functions, such as an emergency lighting device, that alsoincorporates a variable TIR lens assembly, such as those illustrated inany of FIGS. 1 and 3-12. The signal interface 1387 includes a transducerinterface 1377 and an electrowetting cell driver 1366. The signalinterface 1387 also has inputs to receive transducer control signals andelectrowetting control signals from a controller, such as 25, 27, or 29of FIG. 12. The transducer interface 1377 may receive the transducercontrol signals from the controller and convert the received controlsignals into a voltage or current that is applied to a transducerconfigured as a light source, such as an LED or other light source. Thetransducer interface 1377 may include electronic circuit components bothanalog and digital circuity as well as logic circuits that receive andprocess the received control signals for output as voltages or currentsapplied to the light source-configured transducer.

Alternatively, when the transducer is configured as a light detector,the transducer interface 1377 is configured to receive signals from thetransducer indicative of a characteristic of the detected light, such asbrightness, intensity, phase, wavelength (e.g., infrared, near-infrared,color or the like). In such a configuration, the transducer interface1377 may receive signals from the transducer, such as 175, and processthe received signals into signals for transmission to a controller, suchas 25, 27 or 29 of FIG. 12.

Regardless of whether the transducer is configured for light emission orlight detection, the signal processing may include digital-to-analogconversion, signal buffering, signal conditioning or other signalmanipulation that facilitates an output from the transducer thatcorresponds to, depending upon the transducer interface configuration,either the received control signal or the received transducer signal.Alternatively, the transducer control signals received from thecontroller may be passed without processing by the transducer interface1377 directly to the transducer as the applied voltage or current.Similarly, the transducer interface 1377 may pass the signals receivedfrom the transducer to another device, such as a controller or gatewaydevice, without any processing.

The electrowetting cell driver 1366 includes an input for receiving theelectrowetting control signals delivered to the signal interface 1377and a number of outputs to respective electrodes 1 to N of theelectrowetting cell of a lens assembly, as shown in the examples ofFIGS. 3-11. The electrowetting cell driver 1366 may receive theelectrowetting cell control signals from the controller and convert thereceived control signals into a voltage or current that is applied toelectrodes 1-N of the electrowetting cell, such as 120 of FIG. 1, toplace the electrowetting cell in a state that provides the desiredoptical characteristics for the lens assembly. The electrowetting celldriver 1366 may include electronic circuit components both analog anddigital circuity as well as logic circuits, including a multiplexor thatreceive and process the output signals as applied voltages or currentsto the respective electrodes. The processing may includedigital-to-analog conversion, signal buffering, signal conditioning orother signal manipulation that facilitates an output from the transducerthat corresponds to the received control signal.

Alternatively, in examples when the interface 1387 is configured tooperate with a detection device, the electrowetting cell may be placedin a state that provides in combination with the TIR lens optics, theoptical characteristics that correspond to the desired light detectionattributes, such as receiving light within a narrow field of view, awide field of view or a field of view between the narrowest and thewidest fields of view.

FIG. 13B illustrates another example of a signal interface, such as 180in FIG. 1. The signal interface 1388 of FIG. 13B may be integrated indevices incorporating variable TIR lens assemblies for emitting lightand/or for detecting light, such as those illustrated in any of FIGS. 1and 3-12. The interface 1388, in this example, includes a microprocessor1355, a transducer interface 1357, and an electrowetting cell driver1367. The microprocessor 1355 may receive control signals from acontroller, such as 25, 27, or 29 of FIG. 12. The microprocessor 1355may determine that the received control signals are intended for eitherthe transducer or an electrode. For example, the received control signalmay include a signal value that the microprocessor 1355 is able toidentify, and based on the identification is able to appropriatelyprocess the signal. Based on the determination or the identification,the microprocessor 1355 may pass a light control signal to thetransducer interface 1357, which is processed by the transducerinterface 1357 in a manner similar to that described above withreference to transducer interface 1377 of FIG. 13A, and is applied to atransducer, such as 175, to cause the emission of light by thetransducer 175. If the microprocessor 1355 determines that the receivedcontrol signals are intended for the electrowetting cell, such as 120 ofFIG. 1, the microprocessor 1355 may further determine which of the 1 toN electrodes a voltage or current is to be applied.

Alternatively, in the example of a detection device in which atransducer, such as 175 in FIG. 1, is configured to respond to detectedlight, the microprocessor 1355 may receive signals from the transducerin response to the detection of light by the transducer. In addition,the microprocessor 1355 may receive control signals from a controller,such as devices 25, 27 and/or 29 of FIG. 12 indicating desiredconfigurations of a lens assembly, such as receive light within a narrowfield of view, a wide field of view or a field of view between thenarrowest and widest fields of view within the capabilities of the lensassembly. Based on the received control signals, the microprocessor 1355may generate electrowetting cell control signals that place theelectrowetting cell in a state that provides the field of view or otheroptical characteristics corresponding to a desired light detectionattribute.

Either of the signal interfaces 1387 or 1388 shown in FIG. 13A or 13B,respectively, may also be configured to generate respective controlsignals that are output, via, for example, the respective other output1357 or 1397 to a reservoir management system (not shown), such as apumping mechanism, that either intakes excess fluid from theelectrowetting cell(s) or outputs additional fluid into theelectrowetting cell(s) to provide an even greater range of opticalcharacteristics.

Although shown in each of the examples in FIGS. 13A and 13B, therespective electrowetting cell drivers 1366 and 1377 may be a number ofdedicated drivers that drive individual electrodes 1 to N. So instead ofa single electrowetting cell driver, the respective interfaces 1387 and1388 include 1 to N electrowetting cell drivers.

Unless otherwise stated, any and all measurements, values, ratings,positions, magnitudes, sizes, and other specifications that are setforth in this specification, including in the claims that follow, areapproximate, not exact. They are intended to have a reasonable rangethat is consistent with the functions to which they relate and with whatis customary in the art to which they pertain.

The scope of protection is limited solely by the claims that now follow.That scope is intended and should be interpreted to be as broad as isconsistent with the ordinary meaning of the language that is used in theclaims when interpreted in light of this specification and theprosecution history that follows and to encompass all structural andfunctional equivalents. Notwithstanding, none of the claims are intendedto embrace subject matter that fails to satisfy the requirement ofSections 101, 102, or 103 of the Patent Act, nor should they beinterpreted in such a way. Any unintended embracement of such subjectmatter is hereby disclaimed.

Except as stated immediately above, nothing that has been stated orillustrated is intended or should be interpreted to cause a dedicationof any component, step, feature, object, benefit, advantage, orequivalent to the public, regardless of whether it is or is not recitedin the claims.

It will be understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.Relational terms such as first and second and the like may be usedsolely to distinguish one entity or action from another withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The terms “comprises,” “comprising,”or any other variation thereof, are intended to cover a non-exclusiveinclusion, such that a process, method, article, or apparatus thatcomprises a list of elements does not include only those elements butmay include other elements not expressly listed or inherent to suchprocess, method, article, or apparatus. An element preceded by “a” or“an” does not, without further constraints, preclude the existence ofadditional identical elements in the process, method, article, orapparatus that comprises the element.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. In addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus the following claims arehereby incorporated into the Detailed Description, with each claimstanding on its own as a separately claimed subject matter.

What is claimed is:
 1. A detection device, comprising: a photoreceptivetransducer configured to detect light and generate signals in responseto the detected light; a signal interface coupled to the transducer toreceive the generated signals from the transducer and configured tooutput detection signals based on the received generated signals; and alens of a transparent material having a first index of refraction, thetransparent lens comprising: an optical lens aperture, opposite the lensinterface, configured to receive light from field of view for directionthrough the transparent lens toward the transducer, a lens interface toprovide light to the transducer, and a transparent exterior lens wallextending from the lens interface to the optical lens aperture; and acontrollable electrowetting assembly surrounding the transparent lens,the controllable electrowetting assembly being coupled to the signalinterface and configured to respond to electrowetting signals receivedfrom the signal interface, the controllable electrowetting assemblycomprising: sealed container walls including at least one wall spacedabout the transparent lens, wherein the sealed container walls form afluidic sealed cell with the exterior wall of the transparent lens, ahigh index of refraction liquid and a low index of refraction liquidcontained in the sealed cell, one of the liquids being conductive andthe other of the liquids being an insulator, an electrowetting opticalaperture through one or more of the container walls and extendingoutward from the optical lens aperture, and electrodes coupled to thesignal interface and electrically coupled with at least the low index ofrefraction liquid, wherein: the low index of refraction liquid isresponsive to the electrowetting signals output from the signalinterface, to vary an amount of the exterior wall of the transparentlens covered by the low index of refraction liquid and cause totalinternal reflection of light within the transparent lens to thereby varya direction and/or shape of light received from the field of view viathe electrowetting optical aperture and/or the optical lens aperture. 2.The detection device of claim 1, wherein: an index of refraction of thehigh index of refraction liquid is higher than the first index ofrefraction of the transparent lens, and an index of refraction of thelow index of refraction liquid is lower than the first index ofrefraction of the transparent lens.
 3. The detection device of claim 1,wherein the photoreceptive transducer is a photo-detector, a lightdetecting diode, a photoconductive cell, a photo-emissive cell or aphoto-voltaic cell.
 4. The detection device of claim 1, wherein thetransparent material of the transparent lens is a glass or plastichaving the first index of refraction.
 5. The detection device of claim1, wherein the electrodes of the controllable electrowetting assemblyextend at predetermined positions along a length of the sealed containerwalls in a direction from the lens interface to the optical lensaperture.
 6. The detection device of claim 1, wherein: a narrow field ofview through the optical lens aperture is provided in response to thelow index of refraction liquid extending over a larger amount of thetransparent lens wall than the high index of refraction index liquid. 7.The detection device of claim 1, wherein: a wide field of view throughthe optical lens aperture and the electrowetting optical aperture isprovided in response to the high index of refraction liquid extendingover a larger amount of the transparent lens wall than the low index ofrefraction index liquid.
 8. A device, comprising: a transducer thatconverts optical energy into an electrical signal; and a variable lensassembly, coupled to deliver light to the transducer, comprising: (a) astructurally static lens formed of a transparent material having a firstindex of refraction in a fixed shape, including: a lens interface at aproximal end of the shape to provide light to the transducer; an opticalaperture at a distal end of the shape opposite the proximal end toreceive light from an environment in which the device is located; and anexterior wall that extends from a portion of the lens interface to aportion of the optical aperture; and (b) a controllable electrowettingcell coupled to the exterior wall of the transparent lens, comprising: acontainer wall spaced from the exterior wall of the transparent lens,the container wall and the exterior wall of the transparent lens forminga fluidic leakproof container; an electrode associated with thecontainer wall to receive a control signal; a high index of refractionliquid within the container; and an electrically conductive low index ofrefraction liquid within the container, wherein: the high index ofrefraction liquid and the low index of refraction liquid are immiscible,and in response to a change of the control signal, the high index ofrefraction liquid and the low index of refraction liquid changepositions within the electrowetting cell thereby altering internal lightreflection characteristics of the exterior wall of the transparent lens.9. The device of claim 8, wherein the lens assembly has predeterminedoptical characteristics based on a configuration of the transparentlens, positions of the high index of refraction liquid and the low indexof refraction liquid within the electrowetting cell and a configurationof the transducer.
 10. The device of claim 8, wherein an extent ofchange in positions of the high index and low index of refractionliquids relative to one another is based upon a value of the controlsignal applied to the electrode.
 11. The device of claim 8, wherein: thehigh index of refraction liquid has a first volume; the low index ofrefraction liquid has a second volume; and the ratio of the volume ofthe high index of refraction liquid to the volume of the low index ofrefraction liquid contributes to the alteration of the internal lightreflection characteristics of the exterior wall of the transparent lenswhen a control signal is received.
 12. The device of claim 8, furtherconfigured to: receive light from a narrower field of view through theoptical lens aperture in response to the low index of refraction liquidextending over a larger area of the exterior wall of the transparentlens than an area of the exterior wall of the transparent lens coveredby the high index of refraction liquid.
 13. The device of claim 12,further comprising: a coupling to a signal interface, wherein thetransducer is further configured to: in response to the received light,output via the coupling a signal to the signal interface.
 14. The deviceof claim 8, wherein: the electrowetting cell further comprises: anelectrowetting optical aperture that receives light from the environmentand that is substantially co-planar with the optical aperture of thetransparent lens; and the device is further configured to: receive lightfrom a wider field of view through the optical lens aperture and theelectrowetting optical aperture of the electrowetting cell in responseto the high index of refraction liquid extending over a larger area ofthe exterior wall of the transparent lens than an area of the exteriorwall of the transparent lens covered by the low index of refractionindex liquid.
 15. The device of claim 14, further comprising: a couplingto a signal interface, wherein the transducer is further configured to:in response to the received light, output via the coupling a signal tothe signal interface.
 16. A variable optical detection device,comprising: a light detector that converts detected light into anelectrical signal; a variable lens assembly that directs input lighttoward the light detector, the variable lens assembly including: astatic, transparent total internal reflection lens, the lens having afirst field of view; and a variable electrowetting cell, including: acontainer forming a fluidically sealed space about the transparent lens;a high index of refraction liquid and a low index of refraction liquidcontained in the sealed space of the cell, one of the liquids beingconductive and the other of the liquids being an insulator, andelectrodes coupled to the variable lens assembly and at leastelectrically coupled with at least the low index of refraction liquid;wherein the variable electrowetting cell is configured to: change afirst field of view of the lens assembly device to a second field ofview, in response to an electrowetting signal applied via theelectrodes.
 17. The variable optical detection device of claim 16,further comprising: a signal interface coupled to the transducer and tothe electrodes, wherein the signal interface is configured to: receiveelectrical signals from the transducer; and deliver electrowettingsignals to the electrodes to control the field of view of the lensassembly.
 18. The variable optical detection device of claim 17, whereinthe low index of refraction liquid is responsive to the electrowettingsignals output from the signal interface, to vary the amount of theexterior wall of the transparent lens covered by the low index ofrefraction liquid to thereby vary the field of view through the variablelens assembly.
 19. The variable optical detection device of claim 17,wherein the transducer is further configured to: in response to thedetected light, output a detection signal to the signal interface. 20.The variable optical detection device of claim 16, wherein the lightdetector is one of a photo-detector, a photoreceptive device, a lightdetecting diode, a photoconductive cell, a photo-emissive cell, or aphoto-voltaic cell.